Carrier effects of dosing the H411E cells with PCB{number_sign}77 (3,3{prime},4,4{prime}-tetrachlorobiphenyl) in DMSO or isooctane

A rat hepatoma cell line, H411E, is used as a bioassay tool to assess the potential toxicity of polychlorinated biphenyl (PCB)-containing environmental samples. PCB exposure to these cells induces cytochrome p45O1A1 activity which is a very sensitive biomarker of toxicity. The objective of this study was to compare the PCB concentration in the H411E cells and the induction of CYPL Al activity as measured by ethoxyresorufin-O-deethylase (EROD) using different carriers, dimethyl sulfoxide (DMSO) and isooctane (TMP). Three micrograms of UL-{sup 14}C-PCB{number_sign}77/plate was dissolved in DMSO or TMP and the cells were dosed with them. The H411E cells were harvested and the PCB{number_sign}77 concentrations and EROD activity at 1,2,4,8,12 hours, and 1,2,3,4 day postexposure measured. EROD activity was higher using in DMSO than TMP. At early timepoints (1--4 hr), PCB{number_sign}77 was taken up quickly with both carriers. However, by day 3 and 4 radioactivity in cells decreased by 5--15% of the initial uptake.